Apparatus for embossing superconducting tape for use in a superconducting magnet

Abstract

An apparatus for manufacturing embossed foil for use in controlling the flow of the molten metal tin plating provided in forming laminated tape for use in superconducting magnets utilizing meshing knurling rollers with truncated paramydical elements arranged to provide and embossed pattern for uniform and controlled flow of the tin.

What we claim is: 
     
       1. Apparatus for uniformly embossing by deforming long lengths of foil for use in liquid coated multi-layer tape for superconducting magnets to control the flow of the liquid metal layer formed on the surface of the foil comprising: a pair of rotatable knurling rollers each having an axis of rotation and positioned contiguous to each other and forming an embossing region between the circumferential surfaces thereof;   each of said circumferential surfaces including a repetitive knurled tooth pattern which substantially mesh and nest in said embossing region;   further providing liquid metal coating means;   means to pass said deformable foil between the meshing and nested teeth and through said embossing region to deform said foil with channels formed between the teeth of said tooth pattern to subsequently control the flow of liquid metal on the surfaces of said foil; and   means to control the relative positioning of said knurling rollers in said embossing region to control the embossing of said knurled pattern onto said foil and said subsequent flow of liquid metal.   
     
     
       2. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 1 wherein said means to pass said foil through said embossing region includes passing said foil through an S-shaped configuration to control wandering of said foil in the direction parallel to said axis of rotation to maintain meshing of said teeth. 
     
     
       3. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 2 wherein said pattern on each of said rotatable knurling rollers comprises a plurality of rows of truncated pyramids to provide a knurl pattern with bases forming the flow control channels therebetween which are substantially parallel and substantially transverse to the length of the said foil; said liquid coating means including a reaction oven, and means to pass said foil vertically through said reaction oven wherein liquid metal flow is influenced by gravity and said substantially parallel and transverse channels. 
     
     
       4. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 3 wherein the crests of said truncated pyramids of said pattern are flatted substantially parallel to said foil and said crests include rounded corners. 
     
     
       5. Apparatus for uniformly embossing long lengths of foil for superconducting magnets of claim 4 wherein the said pyramids are truncated four sided pyramids with flatted four sided tops. 
     
     
       6. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 5 wherein said means to control the relative positioning of said knurling rollers includes a sensor and an adjustable camming surface for adjustably axially positioning at least one of said rotatable knurling rollers transverse to said foil in said embossing region to provide said nesting of said truncated pyramids. 
     
     
       7. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 6 wherein the bases of said pyramids are with the bases positioned in alignment transverse to the direction of movement of said foil in passing through said embossing region and forming flow paths in the channels between adjacent rows of said pyramids which are transverse to the direction of movement of said foil through said embossing region. 
     
     
       8. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 6 wherein said adjustment means includes an adjustable camming surface to adjust the position of one of said rollers radially to the other of said rollers to adjust the depth of the deformation and said channels. 
     
     
       9. Apparatus for uniformly embossing long lengths of foil for superconducting magnets of claim 1 wherein said foil is NbZr. 
     
     
       10. Apparatus for uniformly embossing long lengths of foil for superconducting magnets of claim 9 wherein said liquid metal layer is tin and said tape is Nb 3  Sn. 
     
     
       11. Apparatus for uniformly embossing and coating long lengths of foil for superconducting magnets of claim 1 wherein adjustment means are provided to adjust the relative position of said knurling rollers along the axes thereof to adjust said mesh; and, further including means to pass the coated foil vertically through a heated reaction oven to uniformly reflow the liquid metal with the assistance of said channels. 
     
     
       12. Apparatus for uniformly embossing and coating long lengths of NbZr foil for use in multi-layer tin coated Nb 3  Sn tape for superconducting magnets to control the flow of the liquid metal layer formed on the surface of the foil comprising: a pair of rotatable knurling rollers each having an axis of rotation and positioned continuous to each other and forming an embossing region between the circumferential surfaces thereof;   each of said circumferential surfaces including a repetitive knurled tooth pattern which substantially mesh in said embossing region;   means to pass said foil between the meshing teeth and through said embossing region; and   means to control the relative positioning of said knurling rollers in said embossing region to control the embossing of said knurled pattern onto said foil   and further including a tin coating means, and means to pass said foil through a heated reaction oven with said embossed pattern controlling the flow of tin on the surfaces of said foil during formation of said Nb 3  Sn tape.   
     
     
       13. Apparatus for uniformly embossing long lengths of foil for superconducting magnets of claim 12 wherein said pattern is configured to provide embossed tin flow channels substantially parallel and substantially transverse to the length of said foil. 
     
     
       14. Apparatus for uniformly embossing long lengths of foil for superconducting magnets of claim 13 wherein said foil is passed substantially vertically through said heated reaction oven and said flow of tin in said reaction oven is subject to the effects of gravity.